A digital signature is the public-key equivalent of message authentication codes. As mentioned by Ferguson [7], the main problem is that (Alice) most of the time does not sign the message herself, but her computer automatically signs the messages for her. Thus, the signature only means that the message comes from Alice's account but it may not be Alice who is the one producing the message. Since the signature is automatic, Alice may not notice or be aware of this fact.
In this patent, we present two different and complementing approaches for the communication between two parties (i.e. Alice and Bob). The first approach is for the case when Alice and Bob frequently communicate with each other (i.e. they know the existence of each other), and the other approach is when they communicate but are not know to each other. In both cases as a minimum, the sender Alice is going to be required to perform an action, which is to type a text sent by the future message recipient. Alice will have to type and send the results of the rhythm of typing such a message. We assume that Alice's computer has the application software to collect such rhythm information. With Alice's rhythm, Bob will use Alice's rhythm information in his possession or use a third party agency that has Alice's rhythm information to assess if Alice is the sender. Therefore, the recipient will be able to trust more the authenticity of the sender. There are some previous patent efforts done by using the rhythm of typing for the purpose of authentication in electronic devices [1], [4], [8], and [9] and [12], many recent patents for secure network communications [14], [15] and [16] and many academic papers [2], [6], [10] and [11], but no patent or paper uses rhythm to enhance security protocols for message transmission like we propose in this patent.